Traditional digital networks have been developed to transfer information such as data among digital computer systems and other digital devices. A variety of types of networks, such as Ethernet, have been developed and implemented using diverse information transfer methodologies. These traditional networks utilize communication ports connected to one another via links in a communication network to send and receive data. However, when one of these links degrades (e.g. the near end transmitting path), the corresponding far end port (e.g. far end receiving port) may continue to receive some data via the corresponding media (e.g., fiber). Accordingly, devices connected to the degraded link operate under a false perception that the link is operating properly. By the time the error is diagnosed, however, substantial data loss may occur.
Link Loss Forwarding (LLF) exists (e.g. is used in existing Ethernet media converters) that disables a far end signal when a loss of input signal at an end of a circuit occurs. In other words, loss of a valid signal or loss of link is forwarded to the far end. For example, intermediate transport failure such as SONET can cause the link to be dropped. LLF is used to signal a line failure in systems that may not be able to respond to a dropped communication path quickly. After disabling the far end, the system may switch to an alternative path, or a network administrator may then be informed of the disconnection immediately and react as promptly as possible to the situation, in an attempt to minimize losses.
This LLF technique, however fails to provide adequate tools for determining link degradation or resolution measures for suspected link degradation. For example, if traffic is being carried over aggregated transport (e.g., multiple lines) using Link Access Control Protocol (LACP), one low quality line can result in sufficient retransmission requests to overwhelm the remaining good transport. In other words, the system would be better served if the poor quality line were shut down.
Current systems lack the ability to determine link degradation that may lead to link failure. Thus, a need exists for enhanced LLF that automatically and proactively determines link degradation. Further, a need exists for enhanced LLF that provides options following a determination of link degradation such as instituting at least a temporary block transport mode and restoring links when a link that indicated excessive errors is working adequately (e.g., at a selected minimal error rate) for a selected period of time.